The Yonah, branded name Core Duo (or Solo), still has power to be unveiled!
MatBe (in French) has successfully overclocked a 2.16GHz Core Duo to 3.0GHz while using an air-based cooling system. Another user reports a massive overclock to 3.8GHz with a Pelletier-based cooling system. With such clock speed, the Core Duo is a benchmarks killer.
But the life of the Core Duo is approaching already to the end (for high-end computers), with the release of the Merom this summer; and first benchmarks of the Merom already start populating the web.
The website
IamExtreme has compared a Merom to a Yonah, both CPU being clocked at 2.16GHz. According to the test, the Merom is faster than the Yonah, from couple of percentage up to 20. In addition keep in mind, the Merom will also be introduced with higher clockspeed and higher bus frequency, so performance gains might be higher than projected today.